Reciprocating rock drill for supplying water to bore holes during drilling



W. E. NETTLE, P. SELBY, J. BLYTHE, AND J. H. HOLMAN. RECIPROGATING ROCK DRILL FOR SUPPLYING WATER T0 BORE HOLES DURING'DRILLING.

APPLICATlON FILED JULYZI. I920.

Patented Sept. 12,1922.

7 .1; l1 2 MN 0 1 J J 3Q m 1 8 a n \N mm m f 4 lw 3 a 17 2 5%! 2 Patented Sept. 112, 1922.

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WIL IAM. nnwrnn-nrrrn, .IPAUL ,SEL'BY, Jarins BLYrnn, AND JOSEPH HENRY I 1 nomvran, or aonannnsnnne, TBANSVAAL, sour AFRICA.

.nncrrnocerinenocx nnrrr. FORHSUIPPLYING warns. TO BORE Horns r t nnrnrrne.

DURING 'Application filed July 21, 1920. Serial No. 398,024.

T 0 all whom it mag concern Be it known that we, "WILLIAM NETTLE, a subje'ctof the King of Great Brit ain, PAUL SnLer, "a citizen of the United States, JAMns BLYTHE, a subject of the King ofGreat Britain, and J osnPrrHnNRY HOL- MAN, a subject of the King of Great Britain,

. all residents of Johannesburg, Transvaal Province, Union ofSouth Africa, have in Vented certain new and usefullmprovements Appertainingto Reciprocatin Rock Drills, for Supplying l/Vater'to Bore Holes During Drilling, of which the following-isa specifi- Cation.

This invention has reference to watersupplying means or attachments for those types of rock-drills and rock-drilling machines called reciprocating drills,

The kind of water-supplying means to whichthe j invention more particularly relates is that in which the water is led through a tube into the; reciprocating parts of the drill,-and thence through the-bit or steel.

With water-supplying-means of the nature referred to, difliculty has been experienced in'preventing the water le'aking in a backward direction from the waterpassage or conduit, which is formed through the r ecip rocating parts, intothe cylinder.' It is es sential that this backward' leakageshall be prevented, as itinterferes with the due op eration of the drill and i'n tin'ie'results in serious disorganization thereof.

It is the primary object of'this invention to overcome't-his difiicu'lty, and toattain the desired'end :in a simple, inexpensive and effective manner. By obviatln'g the difficulty in the manner hereinafter explained, we are able to 'simplify and improye" the general construction of such water-supplying means.

The present invention is characterized by a construction in which prov sion is made foradmitti ng and maintainin'ga supply of air under pressure into a'yspace or chamber which is'so positioned-that the pressure of said :a'ir'operatesinall positions of the piston, to preclude the passage of water in a 1 direction'rearwardly of said-space or chamber.

In the accompanyingdrawings we illustrate a practical embodiment of the invention, whereinv v ga-par t longitudinal section of a EDWIN l tion between the water-supply tube and the back cover of the drill.

Fig. 1 of the drawings shows the complete arrangement, and in this figure, l indicates the cylinder ofthe rock-drill, 2 being the piston, which reciprocates in the cylinder 1. 3 is the piston rod, 4 the chuck or holder for the bit or steel and 5 the bit or steel 8 is the axial passage or conduit along whichthe water passes, which passage extends through the aforementioned parts 3, 4,

and 5, and terminates at the cutting extremity'9 of the bit or steel 5. 10 is the cylinder back cover, 11 the rifle bar and 12 the ratchet wheel of the rotation mechanism; 12 the rifie nut, fixed in the rear end of the piston 2 and engaged by the rifle bar 11 in the ordinary manner.

The water supply means include the tube 13, which is connected to and supported by the back cover 10 and extends in a forward direction through an axial hole in the rifle bar 11, through the piston 2 and into the passage or conduit 8, through the piston rod For", the purpose of attaching said tube 18 to the back cover and suitably connecting it with the water supply means, the tube 13 is 'shown constructed with a head or enlargement -14, which'is seated in a recess or counterbore'15 in the rear'end ofa spud or coupling member 16. 17 represents'packing between the head or enlargement 14 and the bottom of the recess or counterbore 15. is an elbow piece or bend the outer end of which, 19, is threaded for making suitable connection between it and a hose or other suitable preferably flexible pipe which conveys the water to the machine. 20 is a gland or nut for retaining the elbow or bend 18 in position against the end of the spud or coupling member 16; 21 being packing be tween a flange 22 formed on the bend and the end of the spud 16. This connection permits the elbow or bend 18 to be rotated about its point of attachment to the spud 16 as may be necessary in manipulating or working the drill. The spud 16 is screwed into a recess 23 in the back cover 10, and between its front end and the bottom of the recess 23 packing 24L is placed which surrounds the tube 13 and forms a gasket between the back cover 10 and the tube 13. It is is to be understood that any other appropriate mode of attaching the water supply tube to the cylinder back cover may be, adopted in lieu of that shown and described.

At the rear of the passage or conduit 8 through the piston rod, there is screwed or otherwise secured a nut or bush 25 of brass or other suitable metal or material. The water tube 13 projects forwardly through this nut or bush 25, which has a loose fit on the tube 13, so that the piston 2 can reciprocate freely over it, and at the same time permit a small quantity of the compressed air or actuating fluid to pass between said water tube 18 and bush 25 in a forward direction during the forward stroke of the piston.

Around the tube 13, forward of the nut or bush 25, an annular space or chamber 26 is provided which receives a supply of air under pressure in all positions of the piston 2. The diameter of the rear end of the passage or conduit 8 forward of the aforesaid annular space or chamber 26 and the external diameter of the water tube 13 are such as to form or provide clearance to allow air to pass in a forward direction from the annular space or chamber 26 through the passage or conduit 8, and in that way prevent the water passing in a. backward direction into the space or chamber 26, whence it would pass into the piston between the exterior of the tube 13 and the bore of the nut or bush 26.

A small hole or port 27 is formed in the front end of the piston which places the cylinder in communication with the space or chamber 26. This port 27, on the backward stroke of the piston 2, allows a small quantity of air under pressure to pass from the interior of cylinder 1 to said space or chamber 26 and thence alon the conduit 8 in a forward direction.v T716 compressed air which enters the chamber 26 between the bush 25 and tube 13 on the forward stroke of the piston and the compressed air which enters said chamber through port 27 on the backward stroke of the piston, by passing between the tube 13 and conduit 8, and along conduit 8, precludes the passage of the water in a reaiuvard direction from conduit Sinto the space or chamber 26, as previously explained. Itis requisite so to control the supplies of compressed air and water to the drill that the passage of the air into the cylinder takes place before the water passes to the tube. 7 i v The construction above described obviates the necessity for the use of packing either at the back or front of the nut or bush and by admitting of the attachment of the water supply tube to the cylinder back cover it enables the water-holding vessel, which has been connected to the back cover in certain known arrangements, to be dispensed with.

What we claim as our invention, and desire to protect by Letters Patent is 1. In a rock-drill, in combination, a cylinder, a reciprocating piston in said cylinder, a drill steel operably connected to the piston, said piston and steel having a passage through which water passes to the bore hole, the reciprocated parts having a space which is placed in communication with the cylinder at both the front and back of the piston, and a water supply tube which passes through the piston and said space to convey water to the passage through the reciprocated parts.

2. In a. rock drill, in combination, a cylinder, a reciprocating part in said cylinder, a drill steel connected to said part, a passage through said part and steel for leading water to the bore hole, a tube connected to the cylinder and over which'the piston works, a chamber in said reciprocated part around the tube, the said part having a port placing the interior of the cylinder at the front of the piston in communication with said chamber to admit and maintain a supply of air under pressure to said space during the backward stroke of the piston, as and for the purpose set forth.

3. In a rock drill, in combination, a cylinder, a reciprocating piston in said cylinder, a piston rod connected to said piston, and a drill steel connected to said piston rod, the piston, piston rod and steel having a passage for leading water to the bore hole, a water supply tubeattached to the cylinder and projecting into the piston and communicating with said water'passage,

one of the reciprocated parts being constructed to form a chamber around said tube and having a port placing; said chamber in communication with the cylinder at the front of the piston. and a bush which forms a loose guide for the tube at the rear of said chamber, thereby forming a passage which places the cylinder at the back of the piston also in communication with said chamber.

4:. In combination, a rock drill cylinder, a reciprocating piston in said cylinder, a piston rod attached to said piston, a drill steel fixed to the front of said piston rod, the piston, piston rod and steel having a passage extending therethrough for leading water to the bore hole, a water supply tube fixed at the rear end of said cylinder and projecting into the aforesaid passage, means for leading water into the rear end of saidtube, the reciprocated parts having a chamber surrounding the tube, and a port placing said chamber in communication with the cylinder at the front of the piston, and a bush loosely surrounding the tube and form-r ing the rear of the chamber, and providing a passage which places the cylinder at the rear of the piston in communication With said chamber.

5. In a rock drill, in combination, a cylinder, a reciprocating part in said cylinder, a drill steel connected to said part, a passage through said part and steel for leading Water to the bore hole, a tube connected to the cylinder and over Which the piston Works, a chamber in said reciprocated part around the tube, a bush fitted in the reciprocated part, which bush Works loosely over the tube thereby placing the interior of the cylinder at the back of the piston in communication With said chamber to admit and maintain a supply of air under pressure to said chamber during the forward stroke of the piston, as and for the purpose set forth. 4

In testimony whereof We have signed our names to this specification in the presence of two subscribing Witnesses.

WILLIAM EDWIN NETTLE. PAUL SELBY.

JAMES BLYTHE.

JOSEPH HENRY HOLMAN.

Witnesses CHAs. WENDAL, ARTHUR THOMPSON. 

